Problem 45220. Find triangles from edge

First input is T, a Triplet list of indices -whom each row actually contains the three indices of a triangle vertices-. size(T) = [nb_triangles, 3]. Second input is e = [e1, e2], a row vector, couple of indices. Output S is the triplet list of indices which Share the edge e. For instance, if

e = [2, 4]

and T a tetrahedron

T = [1, 2, 3;...
1, 3, 4;...
1, 2, 4;...
2, 3, 4]

then the output of the function is

S = [1, 2, 4;...
2, 3, 4]

since both triangles [1, 2, 4] and [2, 3, 4] contain the edge [2, 4].

Conditions :

If the edge is not part of any triangle in the list, the function must of course return the empty set, [].

Solution Stats

Last 200 Solutions

Problem Comments

Info : T is actually a triangulation -list of triangles-, in which each index corresponding to the row index of a vertex in another list -a vertices list-, it is a widely used technique used to store and write triangular meshes in mesh processing. Here below the example is a tetrahedron -4 facets-.